Evaluation of topotecan in resistant and relapsing multiple myeloma: a Southwest Oncology Group study.
OBJECTIVE
Topotecan is a topoisomerase I inhibitor with antitumor activity against hematologic and solid tumor malignancies. We evaluated its activity in refractory and relapsing multiple myeloma patients who had received one prior chemotherapeutic regimen.


METHODS
Toptecan 1.25 mg/m2/d was administered as a 30-minute infusion for 5 days repeated every 3 weeks. Granulocyte colony-stimulating factor (G-CSF) 5 microg/kg/d subcutaneously was administered after the first course of treatment if neutropenia was dose-limiting.


RESULTS
Forty-six patients entered the study, with 43 patients eligible. The major toxicity was granulocytopenia with grade 3 or better occurring in 40 of 43 patients treated; 21 of 43 patients developed grade 3 or greater thrombocytopenia. Other significant toxicity included mild nausea in 23 patients and mild vomiting in 13 patients. The overall response rate (partial response or better) was 16% (95% confidence interval, 7% to 31%), with responses occurring in both relapsed and refractory patients. Responses have lasted 70 to 477+ days, with a median progression-free survival duration of 13 months and median survival time of 28 months.


CONCLUSIONS
Topotecan has activity in refractory and relapsing multiple myeloma. Future investigation of topotecan in multiple myeloma including combination therapy and the study of other topoismerase I inhibitors is warranted.
Kraut
E H
EH
Ohio State University, Columbus, USA.
Crowley
J J
JJ
Wade
J L
JL
Laufman
L R
LR
Alsina
M
M
Taylor
S A
SA
Salmon
S E
SE
D000328:Adult; D000368:Aged; D000970:Antineoplastic Agents / Q000009:adverse effects / Q000627:therapeutic use*; D019008:Drug Resistance, Neoplasm; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009101:Multiple Myeloma / Q000188:drug therapy* / Q000401:mortality; D012008:Recurrence; D015996:Survival Rate; D019772:Topotecan / Q000009:adverse effects / Q000627:therapeutic use*
D000970:Antineoplastic Agents; D019772:Topotecan